EM Loop: The Tech Deep-dive Interview

In this type of interview, you’re expected to dive into one of your past projects and explain its technical aspects and design in detail. Remember that the interviewer is mainly looking at your capability to confidently hold a tech discussion and discuss things like trade-offs. The interviewer also looks at how well you communicate when presenting difficult concepts. Practice ahead of time by drawing design and architecture diagrams and walking through the design of a past project. Think of it more like an informal system design review presentation or discussion.

Note: Make sure to check with the recruiter which tools (a physical whiteboard, Google Jamboard) will be available to you during the interview and practice with the same tools beforehand. It’s a good idea to practice a mock interview with a friend or to record yourself since you can choose the project beforehand and are given the opportunity to prepare.

Useful tips#

A few tips to keep in mind when answering questions during this interview are as follows:

• Lead with the customer: It’s always good to start with who benefits from the project that your team built and how it solves a customer pain point.

• Know your numbers: It’s important to highlight how your team used data-driven approaches to make key decisions about the architecture of your system. You should know metrics like Daily Active Users and Concurrent Users for user-facing products and request and error rates for back-end products.

• Operational excellence: You should prepare to talk about how you monitored the health of your system in production. When drawing out the architecture diagram, mention the auxiliary systems that were needed for observability, such as logging, tracing, monitoring, and alerting.

• Scalability: This is something the interviewer may not explicitly ask. However, with any company operating at scale, the interviewer will be looking for bottlenecks in your system. For instance, when your workload increases 10x or 100x, can your system scale horizontally, or does it fall over?